Which element is the most abundant in the Earth's crust?
A
Silicon
B
Aluminum
C
Iron
D
Oxygen
Correct Answer: Option D — Oxygen
Explanation:
Oxygen is the most abundant element in the Earth's crust making up approximately 46% by mass. It is found primarily in silicate minerals. Silicon is the second most abundant. Despite being a gas at standard conditions oxygen is bound in rocks and minerals making it the dominant crustal element.